Plasticizer Composition, Resin Composition, and Method of Preparing the Same

ABSTRACT

Provided herein are a plasticizer composition, a resin composition, and a method of preparing the plasticizer composition. A plasticizer composition capable of enhancing poor physical properties occurring due to structural limitations and enhancing physical properties such as tensile strength, migration resistance, volatile loss, and the like, which are required when used as a plasticizer of a resin composition, and a resin composition including the same may be provided.

CROSS-REFERENCE TO RELATED APPLICATION

This application claims priority to and the benefit of Korean PatentApplication Nos. 10-2015-0105323, filed on Jul. 24, 2015, and10-2016-0092873, filed on Jul. 21, 2016, the disclosure of which isincorporated herein by reference in its entirety.

TECHNICAL FIELD

The present invention relates to a plasticizer composition, a resincomposition, and a method of preparing the plasticizer composition.

BACKGROUND ART

Generally, in plasticizers, an alcohol reacts with a polycarboxylic acidsuch as phthalic acid and adipic acid to form an ester correspondingthereto. In addition, in consideration of domestic and foreignregulations of phthalate-based plasticizers which are harmful to thehuman body, research on plasticizer compositions that can replacephthalate-based plasticizers such as terephthalate-based plasticizers,adipate-based plasticizers, other polymer-based plasticizers, and thelike has been continuously conducted.

Meanwhile, to manufacture products such as flooring materials,wallpaper, sheets, interior and exterior materials for automobiles,films, electric wires, and the like, the use of a suitable plasticizeris required in consideration of migration, volatile loss, extension,elongation, plasticizing efficiency, and the like. According toproperties required according to the type of industry in such variousapplications, i.e., tensile strength, elongation, light resistance,migration, gelation properties, and the like, a PVC resin is mixed witha plasticizer, a filler, a stabilizer, a viscosity reducing agent, adispersant, an antifoaming agent, a foaming agent, or the like.

For example, from among plasticizer compositions applicable to PVC, wheninexpensive diethylhexylterephthalate is used, plasticizing efficiencyis low, an absorption rate of the plasticizer is relatively low, andlight resistance and migration are also poor.

Therefore, there is a need to develop products of a novel composition,such as products with superior properties to diethylhexylterephthalate,and continuously conduct research on the most suitable technology forthe use thereof as a plasticizer for vinyl chloride-based resins.

DISCLOSURE Technical Problem

Therefore, the inventors of the present invention continuously conductedresearch on plasticizers and verified a plasticizer composition capableof enhancing poor physical properties occurring due to structurallimitations, thus completing the present invention.

That is, an object of the present invention is to provide a plasticizercapable of enhancing physical properties, such as plasticizingefficiency, migration, gelation properties, light resistance, and thelike which are required for formulation of sheets and the like, whenused as a plasticizer of a resin composition, a method of preparing thesame, and a resin composition including the plasticizer.

Advantageous Effects

A plasticizer composition according to an embodiment of the presentinvention can provide excellent physical properties, such as highplasticizing efficiency, high tensile strength and high elongation aswell as high migration resistance, high volatilization resistance, andthe like, when used in a resin composition, and, in particular, may besuitable for use in resin products which have high plasticizingefficiency and a high absorption rate, and the like and requireenvironmentally-friendly plasticizers according to the use of vegetableraw materials.

DESCRIPTION OF DRAWINGS

FIG. 1 is an image showing thermal stability test results of samples ofexamples and comparative examples.

BEST MODE OF THE INVENTION Examples

Hereinafter, the present invention will be described in detail withreference to the following examples. However, the examples according tothe present invention may be changed in many different forms and shouldnot be construed as being limited to the embodiments set forth herein.Rather, these examples are provided so that this disclosure will bethorough and complete, and will fully convey the scope of the presentinvention to those of ordinary skill in the art.

Preparation Example 1: Preparation of DEHTP

498.0 g of purified terephthalic acid (TPA), 1170 g of 2-ethylhexylalcohol (2-EH) (a molar ratio of TPA: 2-EH=1.0:3.0), and 1.54 g (0.31parts by weight with respect to 100 parts by weight of TPA) of atitanium-based catalyst (tetraisopropyl titanate (TIPT)) were added to a3 L four-neck reactor equipped with a cooler, a condenser, a decanter, areflux pump, a temperature controller, a stirrer, and the like, and thetemperature of the reactor was slowly raised up to about 170° C. Thegeneration of produced water started at about 170° C., an esterificationreaction was performed at a reaction temperature of about 220° C. underan atmospheric pressure condition for about 4.5 hours while continuouslyintroducing nitrogen gas, and the reaction was terminated when an acidvalue reached 0.01.

After the reaction was completed, distillation extraction was performedunder reduced pressure for 0.5 hours to 4 hours to remove unreacted rawmaterials. Steam extraction was performed for 0.5 hours to 3 hours underreduced pressure using steam to remove the unreacted raw materials at apredetermined amount level or less. A temperature of a reaction solutionwas cooled to about 90° C. to perform neutralization treatment using analkaline solution. In addition, washing may also be performed andthereafter, water is removed by dehydrating the reaction solution. Afilter medium was introduced into the dehydrated reaction solution andstirred for a certain period of time, followed by filtration, therebyfinally obtaining 1,326.7 g (yield: 99.0%) ofdi(2-ethylhexyl)terephthalate.

Preparation Example 2: Preparation of DINTP

DINTP was prepared in the same manner as in Preparation Example 1 exceptthat isononyl alcohol was used instead of using 2-ethylhexyl alcoholduring the esterification reaction.

Preparation Example 3: Preparation of DEHTP/BEHTP/DBTP Mixture (FirstMixture)

2,000 g of di(2-ethylhexyl)terephthalate and 340 g (17 parts by weightbased on 100 parts by weight of DEHTP) of n-butanol were added to areactor equipped with a stirrer, a condenser, and a decanter, and then atrans-esterification reaction was performed at a reaction temperature of160° C. for 2 hours under a nitrogen atmosphere to obtain an ester-basedplasticizer composition including 4.0 wt % of di butyl terephthalate(DRIP), 35.0 wt % of butyl(2-ethylhexyl)terephthalate (BEHTP), and 61.0wt % of di(2-ethylhexyl)terephthalate (DEHTP).

The reaction product was subjected to mixed distillation to removebutanol and 2-ethylhexyl alcohol, thereby completing the preparation ofa first mixture.

Preparation Example 4: Preparation of DINTP/EHINTP/DEHTP Mixture (ThirdMixture)

498.0 g of purified terephthalic acid (TPA), 975 g of 2-ethylhexylalcohol (2-EH) (a molar ratio of TPA: 2-EH=1.0:2.5), 216.5 g of isononylalcohol (INA) (molar ratio of TPA:INA=1.0:0.5), and 1.54 g (0.31 partsby weight with respect to 100 parts by weight of TPA) of atitanium-based catalyst (tetraisopropyl titanate (TIPT)) were added to a3 L four-neck reactor equipped with a cooler, a condenser, a decanter, areflux pump, a temperature controller, a stirrer, and the like, and thetemperature of the reactor was slowly raised up to about 170° C. Thegeneration of produced water started at about 170° C., an esterificationreaction was performed at a reaction temperature of about 220° C. underan atmospheric pressure condition for about 4.5 hours while continuouslyintroducing nitrogen gas, and the reaction was terminated when an acidvalue reached 0.01.

After the reaction was completed, distillation extraction was performedunder reduced pressure for 0.5 hours to 4 hours to remove unreacted rawmaterials. Steam extraction was performed for 0.5 hours to 3 hours underreduced pressure using steam to remove the unreacted raw materials at apredetermined amount level or less. A temperature of a reaction solutionwas cooled to about 90° C. to perform neutralization treatment using analkaline solution. In addition, washing may also be performed andthereafter, water is removed by dehydrating the reaction solution. Afilter medium was introduced into the dehydrated reaction solution andstirred for a certain period of time, followed by filtration, therebyfinally obtaining a third mixture.

For reference, the mixture of Preparation Example 4 may also be preparedby performing a trans-esterification reaction using isononyl alcohol,instead of using 2-ethylhexyl alcohol in Preparation Example 3.

Preparation Example 5: Preparation of Epoxidized Fatty Acid Butyl Ester(eFABE)

A trans-esterification reaction was performed using 500 g of epoxidizedsoybean oil and 490 g of butanol as reaction raw materials, therebyfinally obtaining 510 g (yield: 95%) of epoxidized butyl soyate.

Preparation Example 6: Preparation of Epoxidized Fatty Acid 2-EthylhexylEster (eFAEHE)

584 g (yield: 95%) of epoxidized 2-ethylhexyl soyate was prepared in thesame manner as in Preparation Example 5, except that 490 g of2-ethylhexyl alcohol was used instead of 490 g of butanol.

Compositions of examples and comparative examples using the materialsprepared according to Preparation Examples 1 to 6 are shown in Tables 1to 5 below.

TABLE 1 eFAAE Mixing TP-based material material weight ratio Example 1-1DEHTP eFABE 7:3 Example 1-2 DEHTP eFABE 5:5 Example 1-3 DEHTP eFAEHE 7:3Example 1-4 DEHTP eFAEHE 5:5 Example 1-5 DEHTP eFAEHE + 7:3 eFABE (5:5)

TABLE 2 eFAAE Mixing TP-based material material weight ratio Example 2-1DINTP eFABE 7:3 Example 2-2 DINTP eFABE 5:5 Example 2-3 DINTP eFAEHE 7:3Example 2-4 DINTP eFAEHE 5:5 Example 2-5 DINTP eFAEHE + 7:3 eFABE (5:5)

TABLE 3 eFAAE Mixing TP-based material material weight ratio Example 3-1DEHTP/BEHTP/DBTP eFABE 7:3 Example 3-2 DEHTP/BEHTP/DBTP eFABE 5:5Example 3-3 DEHTP/BEHTP/DBTP eFAEHE 7:3 Example 3-4 DEHTP/BEHTP/DBTPeFAEHE 5:5 Example 3-5 DEHTP/BEHTP/DBTP eFAEHE + 5:5 eFABE (5:5)

TABLE 4 TP-based eFAAE Mixing Third material material weight ratiocomposition Example 4-1 DEHTP eFABE 7:3 ESO (60 parts by weight) Example4-2 DINTP eFAEHE 7:3 ESO (100 parts by weight) Example 4-3 DEHTP/ eFABE7:3 ESO (40 parts BEHTP/ by weight) DBTP

TABLE 5 First Second Mixing composition composition weight ratioComparative DEHTP — — Example 1 Comparative DINTP — — Example 2Comparative DEHTP/BEHTP/DBTP — — Example 3 Comparative DEHTP eFAME 5:5Example 4 Comparative DINTP eFAME 5:5 Example 5 Comparative DIDP eFAME7:3 Example 6 Comparative DOP eFAME 7:3 Example 7 Comparative DIDPeFAINE 5:5 Example 8 Comparative DEHTP/BEHTP/DBTP eFAINE 7:3 Example 9Comparative DEHTP/BEHTP/DBTP eFAINE 5:5 Example 10

Experimental Example 1: Specimen Preparation and Performance Evaluation

Experimental specimens were prepared using the plasticizer compositionsof the examples and the comparative examples. With reference to ASTMD638, the specimens were prepared by mixing 40 parts by weight of eachplasticizer composition and 3 parts by weight of a barium-zincstabilizer with 100 parts by weight of PVC in a 3 L super mixer at 100°C. and 700 rpm for 2 minutes and 1,300 rpm for about 10 minutes, andperforming roll milling on the resulting mixture at 160° C. for 3minutes to fabricate a 5 mm sheet.

A press operation was performed on each sheet at 180° C. underlow-pressure for 2.5 minutes, and under high-pressure for 2 minutes, anda cooling operation was performed for 3 minutes, and then a 1 to 3 mmsheet was fabricated and prepared into several type C dumbbell-shapedspecimens. A test for evaluating the following physical properties wasconducted using each specimen.

<Test Items>

Hardness Measurement

Shore (shore “A”) hardness was measured at 25° C. using ASTM D2240.

Tensile Strength Measurement

A breaking point of each specimen was measured after pulling thespecimen at a cross-head speed of 200 mm/min (1T) using a testinstrument, i.e., U.T.M (manufacturer: Instron, Model name: 4466) by anASTM D638 method. Tensile strength was calculated as follows:

Tensile strength (kgf/cm²)=load value (kgf)/thickness (cm)×width (cm)

Elongation Rate Measurement

A breaking point of each specimen was measured after pulling thespecimen at a cross-head speed of 200 mm/min (1T) using the U.T.M testinstrument by an ASTM D638 method, and an elongation rate was calculatedas follows:

Elongation rate (%)=length after elongation/initial length×100

Migration Loss Measurement

Specimens having a thickness of 2 mm or more were obtained according toKSM-3156, and a PS plate was attached to opposite surfaces of eachspecimen and then a load of 1 kgf/cm² was applied thereto. The specimenswere maintained in a hot air circulating oven (80° C.) for 72 hours,taken out thereof, and cooled at room temperature for 4 hours.Thereafter, the PS plates were removed from the opposite surfaces of thespecimen, weights before and after being maintained in the oven weremeasured, and migration loss was calculated using the followingEquation:

Migration loss (%)={(initial weight of specimen at roomtemperature-weight of specimen after maintained in oven)/initial weightof specimen at room temperature}×100

Volatile Loss Measurement

The prepared specimens were heated at 100° C. for 72 hours, and then theweights of the specimens were measured.

A volatile loss of each specimen was calculated as follows:

Volatile loss (wt %)=initial weight of specimen−(weight of specimenafter heated at 100° C. for 72 hours)/initial weight of specimen×100

Absorption Rate Measurement

An absorption rate was evaluated by measuring the time taken to reach astate in which after resin and ester compounds were mixed together usinga planatary mixer (Brabender, P600) at 77° C. and 60 rpm, and a torqueof the mixer was stabilized.

Thermal Stability Measurement

The prepared specimens were heated to 230° C. in a Mathis oven, andcombustion degrees of the specimens were measured.

Performance evaluation results of the specimens according to theabove-described test items are shown in Tables 6 to 10 below, and heatresistance evaluation results thereof are illustrated in FIG. 1.

TABLE 6 Hardness Tensile Elongation Migration Volatile Absorption (Shorestrength rate loss loss rate “A”) (kg/cm²) (%) (%) (%) (sec) Example 1-185.6 230.2 335.6 4.12 2.77 4:57 Example 1-2 84.3 232.4 314.2 4.35 3.084:03 Example 1-3 86.2 247.8 325.6 4.32 2.62 6:08 Example 1-4 85.1 250.3339.5 4.56 2.84 6:49 Example 1-5 85.8 241.5 331.8 4.18 2.68 5:11

TABLE 7 Hardness Tensile Elongation Migration Volatile Absorption (Shorestrength rate loss loss rate “A”) (kg/cm²) (%) (%) (%) (sec) Example 2-187.9 234.4 320.0 5.33 1.74 5:35 Example 2-2 86.4 232.8 325.2 5.67 2.114:22 Example 2-3 88.3 253.3 309.2 5.02 1.52 7:10 Example 2-4 87.3 250.1321.7 5.42 1.89 6:10 Example 2-5 88.1 247.9 315.4 5.24 1.58 6:15

TABLE 8 Hardness Tensile Elongation Migration Volatile Absorption (Shorestrength rate loss loss rate “A”) (kg/cm²) (%) (%) (%) (sec) Example 3-183.4 232.5 352.1 2.25 3.56 4:43 Example 3-2 82.1 235.6 356.8 2.39 3.214:03 Example 3-3 84.4 250.1 360.2 2.51 3.08 5:02 Example 3-4 84.2 255.7362.8 2.74 2.83 4:42 Example 3-5 83.0 250.2 360.9 2.44 2.91 4:21

TABLE 9 Hardness Tensile Elongation Migration Volatile Absorption (Shorestrength rate loss loss rate “A”) (kg/cm²) (%) (%) (%) (sec) Example 4-185.0 252.6 359.7 3.16 1.88 5:12 Example 4-2 86.7 258.9 342.1 3.41 1.026:45 Example 4-3 83.8 254.1 357.8 1.78 2.52 5:10

TABLE 10 Hardness Tensile Elongation Migration Volatile Absorption(Shore strength rate loss loss rate “A”) (kg/cm²) (%) (%) (%) (sec)Comparative 87.4 235.9 310.1 4.00 2.44 7:25 Example 1 Comparative 89.1239.0 303.9 5.35 1.04 8:05 Example 2 Comparative 84.7 230.8 332.3 2.113.84 5:32 Example 3 Comparative 83.2 215.6 308.2 8.41 6.14 2:17 Example4 Comparative 85.1 217.4 310.5 10.52 5.88 2:28 Example 5 Comparative88.7 234.8 284.5 5.62 4.21 9:34 Example 6 Comparative 82.4 218.4 312.44.33 9.51 4:22 Example 7 Comparative 86.4 238.2 265.9 4.37 3.34 11:49 Example 8 Comparative 85.2 234.1 312.5 4.15 3.08 5:25 Example 9Comparative 85.7 238.1 310.2 5.65 3.03 5:11 Example 10

Referring to Tables 6 to 10, it can be confirmed that, when compared toComparative Examples 1 to 3 not including an epoxy-based alkyl estercompound, which is used as an existing general-purpose product havingexcellent basic physical properties while having problems in terms ofprice competitiveness, limited applications, and the like, the specimensof the examples including the same exhibited almost the same mechanicaland physical properties as those in Comparative Examples 1 to 3 andexhibited considerable improvement in absorption rate and migration lossor volatile loss.

In addition, it can be confirmed that Comparative Examples 4 to 10,using an epoxidized methyl ester compound or epoxidized isononyl estercompound not having 4 or 8 carbon atoms from among epoxy-based alkylester compounds, exhibit considerably poor basic mechanical and physicalproperties as compared to the examples. In particular, it can beconfirmed that the plasticizer compositions of Comparative Examples 4 to10 have problems with being used as products due to significantlydeteriorated physical properties thereof in terms of tensile strength orelongation rate, and in the case of Comparative Examples 4 and 5, fairlypoor migration loss properties are exhibited, in the case of ComparativeExamples 4, 5, and 7, fairly poor volatile loss properties areexhibited, and in the case of Comparative Example 8, a much lowerabsorption rate is exhibited.

From the above-described results, it can be confirmed that, when amixture of a terephthalate-based material and an epoxy-based alkyl estercompound wherein the number of carbon atoms of an alkyl is 4 or 8 isused, mechanical and physical properties may be enhanced and there is aconsiderable improvement in migration properties or volatile lossproperties.

In addition, comparing Examples 1-1 to 1-5 with Examples 3-1 to 3.5,Examples 3-1 to 3-5 exhibit a low hardness and a high elongation rate,from which it can be confirmed that the plasticizer compositions ofExamples 3-1 to 3-5 may be suitably used for specific applications.

In addition, it can be confirmed that, when epoxidized oil is includedas an additional composition as in Examples 4-1 to 4-3, migration lossand volatile loss properties are significantly enhanced withoutdeterioration of mechanical and physical properties.

Furthermore, referring to FIG. 1, it can be confirmed that, whenepoxidized oil is additionally included, thermal stability may beenhanced, and the specimen of Comparative Example 1 or 2 was turned intoblack ashes through complete combustion, and the case of Example 1-1 notincluding epoxidized oil was incompletely burned as compared to thecomparative examples, while the case of Example 4-1 including epoxidizedoil exhibited a much lower degree of combustion than that of thecomparative examples or Example 1-1.

MODE OF THE INVENTION

Hereinafter, the present invention will be described in detail.

The terms or words used in the present specification and claims shouldnot be construed as being limited to ordinary or dictionary meanings andshould be construed as meanings and concepts consistent with the spiritof the present invention based on a principle that an inventor canappropriately define concepts of terms to explain the invention of theinventor in the best way.

The term “butyl” as used herein refers to a C₄ alkyl group containingboth a straight chain and a branched chain, and examples thereof includen-butyl, isobutyl, and t-butyl. Preferably, the butyl group may ben-butyl or isobutyl.

The terms “octyl” and “2-ethylhexyl” as used herein refers to a C₈ alkylgroup, and the term “octyl” may be interchangeably used with anabbreviation for 2-ethylhexyl. In some cases, the octyl group may referto octyl as a straight alkyl group, or 2-ethylhexyl as a branched alkylgroup.

Plasticizer Composition

According to an embodiment of the present invention, there is provided aplasticizer composition including: a terephthalate-based material; andan epoxy-based alkyl ester compound, in which a weight ratio of theterephthalate-based material to the epoxy-based alkyl ester compound is99:1 to 1:99, and the epoxy-based alkyl ester compound is a singlecompound or a mixture of two or more compounds.

The plasticizer composition including a terephthalate-based material maybe provided. In particular, the terephthalate-based material may be usedin an amount selected from ranges of 1 wt % to 99 wt %, 20 wt % to 99 wt%, 40 wt % to 99 wt %, 50 wt % to 95 wt %, 60 wt % to 90 wt %, and thelike, based on a total weight of the plasticizer composition.

The terephthalate-based material may be a single compound selected fromthe group consisting of di(2-ethylhexyl)terephthalate (DEHTP),diisononyl terephthalate (DINTP), dibutyl terephthalate (DBTP), butylisononyl terephthalate (BINTP), butyl(2-ethylhexyl)terephthalate(BEHTP), and (2-ethylhexyl)isononyl terephthalate (EHINTP) or a mixtureof two or more of these compounds.

The terephthalate-based material may be a mixture of threeterephthalate-based materials, for example, a first mixture ofdi(2-ethylhexyl)terephthalate, butyl(2-ethylhexyl)terephthalate, anddibutyl terephthalate, a second mixture of diisononyl terephthalate,butyl isononyl terephthalate, and dibutyl terephthalate, or a thirdmixture of di(2-ethylhexyl)terephthalate, (2-ethylhexyl)isononylterephthalate, and diisononyl terephthalate.

In particular, the first, second, and third mixtures may have a specificcomposition ratio. The first mixture may include 3.0 mol % to 99.0 mol %of di(2-ethylhexyl)terephthalate, 0.5 mol % to 96.5 mol % ofbutyl(2-ethylhexyl)terephthalate, and 0.5 mol % to 96.5 mol % of dibutylterephthalate, the second mixture may include 3.0 mol % to 99.0 mol % ofdiisononyl terephthalate 0.5 mol % to 96.5 mol % of butyl isononylterephthalate, and 0.5 mol % to 96.5 mol % of dibutyl terephthalate, andthe third mixture may include 3.0 mol % to 99.0 mol % ofdi(2-ethylhexyl)terephthalate, 0.5 mol % to 96.5 mol % of(2-ethylhexyl)isononyl terephthalate, and 0.5 mol % to 96.5 mol % ofdiisononyl terephthalate.

The composition ratio may be a mixed composition ratio produced by anesterification reaction and may be an intended composition ratio inwhich a specific compound is further mixed. The mixed composition ratiomay be appropriately adjusted according to desired physical properties.

The plasticizer composition includes a terephthalate-based material andan epoxy-based alkyl ester compound. The epoxy-based alkyl estercompound may be represented by Formula 1 below and have an iodine value(I.V.) of less than 4 g I₂/100 g.

wherein, in Formula 1, R₁ is a C₈-C₂₀ alkyl group or an alkyl groupcontaining one or more epoxy groups, and R₂ is a C₄ or C₈ alkyl group.

The epoxy-based alkyl ester compound may have an oxirane value (O.V.) of6.0% or more, 6.3% or more, preferably, 6.5% or more. In addition, theoxirane value may vary according to the number of epoxy groups includedin a substituent denoted as R₁ in Formula 1, may be measured bytitration, and may be measured by a method of ASTM D1562-04 using asample and an acid solution.

In addition, the iodine value of the epoxy-based alkyl ester compoundmay be less than 4 g 12/100 g, preferably, 3.8 I₂/100 g or less. Theiodine value refers to the content of double bonds present in molecules,and may be obtained from values measured by titration through iodinationof the double bonds.

The measured iodine value and oxirane value may be important factorswhen the epoxy-based alkyl ester compound is applied to the plasticizercomposition. In particular, when the iodine value of the epoxy-basedalkyl ester compound is 4 g 12/100 g or more, compatibility of theplasticizer composition with a resin may be significantly reduced andthus the plasticizer composition may not be used as a plasticizer. Whenthe iodine value of the epoxy-based alkyl ester compound is less than 4g I₂/100 g, mechanical and physical properties, such as tensilestrength, elongation rate, absorption rate, and the like, may beenhanced. In addition, the oxirane value may also have a technicalsignificance similar to that of the iodine value and may have a similareffect.

The iodine value may refer to the content of double bonds, and thecontent of double bonds may be the content of double bonds remainingafter performing an epoxidation reaction, such as epoxidation ofvegetable oil, epoxidation of fatty acid alkyl esters, or the like. Thatis, an oxirane value and an iodine value may be indexes for a degree towhich epoxidation proceeds, may be associated with each other to someextent, and may be theoretically in inverse proportion to each other.

However, double bonds of vegetable oil or fatty acid alkyl esters maysubstantially vary according to material, and thus the two parametersmay not accurately form an inverse proportion relation or a trade-offrelation, and, of two materials, a material with a higher iodine valuemay also have a higher oxirane value. Thus, the epoxy-based alkyl estercompound having iodine and oxirane values within the above-describedranges may be applied to the plasticizer composition.

Meanwhile, the epoxy-based alkyl ester compound may have an epoxidationindex (E.I.) of 1.5 or more.

As described above, the iodine value and the oxirane value may satisfythe above-described relation, and, simultaneously, the epoxidation indexmay satisfy a range of 1.5 or more. The term “epoxidation index” as usedherein refers to a ratio of oxirane value to iodine value of theepoxy-based alkyl ester compound, and may be a ratio of double bondsepoxidated by epoxidation to remaining unreacted double bonds.

As described above, when the epoxidation index is less than 1.5 due to asmall amount of an oxirane or a high iodine value, or when epoxidationitself does not proceed, hardness of the plasticizer compositionincreases and thus a plasticizing effect thereof may be significantlydeteriorated, and migration loss and volatile loss properties may alsobe significantly deteriorated.

In particular, the epoxidation index, which is a ratio (O.V./I.V.) of anoxirane value to an iodine value, may be 1.5 or more. That is, when avalue obtained by dividing the oxirane value of the epoxy-based alkylester compound by the iodine value thereof is 1.5 or more, a moresuitable plasticizer composition may be obtained, and, in particular,the plasticizer composition may tend to have increased compatibilitywith a resin.

The epoxy-based alkyl ester compound may be an epoxidized fatty acidalkyl ester (eFAAE), and, in particular, may be represented by Formula 1above, “alkyl” of the epoxy-based alkyl ester compound may have 4 or 8carbon atoms.

However, in the present invention, R₂ of Formula 1 may have 4 to 8carbon atoms, and is preferably a butyl group or a 2-ethylhexyl group.In addition, the epoxy-based alkyl ester compound of Formula 1 may be amixed composition including two or more compounds, and the mixedcomposition including two or more compounds may be a mixture of acompound having 4 carbon atoms and a compound having 8 carbon atoms.When R₂ of Formula 1 is a C₄ or C₈ group, the plasticizer compositionmay have excellent absorption properties and thus exhibit less of agelling phenomenon, may exhibit enhanced processability, excellent basicmechanical and physical properties such as tensile strength orelongation rate, and, in particular, may exhibit excellent migration orvolatile loss properties.

In this regard, a weight ratio of the terephthalate-based material andthe epoxy-based alkyl ester compound included in the plasticizercomposition may range from 99:1 to 1:99, 99:1 to 20:80, or 99:1 to40:60, preferably, 95:5 to 50:50 or 90:10 to 60:40.

As described above, when the mixed plasticizer composition of aterephthalate-based material and an epoxy-based alkyl ester compound isused, high tensile strength and elongation rate may be obtained,improved effects in terms of migration and volatile loss may beobtained, and an absorption rate may be controlled and thusprocessability may also be enhanced.

Method of Preparing a Plasticizer Composition

According to an embodiment of the present invention, there is provided amethod of preparing a plasticizer composition, including: preparing aterephthalate-based material; preparing an epoxy-based alkyl estercompound represented by Formula 1 below by performing an esterificationreaction on epoxidized oil and a C₄ or C₈ primary alkyl alcohol; andmixing the terephthalate-based material and the epoxy-based alkyl estercompound in a weight ratio of 99:1 to 1:99, in which the epoxy-basedalkyl ester compound is a single compound or a mixture of two or morecompounds.

The preparing of the terephthalate-based material and the preparing ofthe epoxy-based alkyl ester compound may be separately performed, andthe materials may be directly prepared through an esterificationreaction and/or a trans-esterification reaction.

The terephthalate-based material may be prepared through a directesterification reaction between terephthalic acid and one or morealcohols selected from primary alkyl alcohols containing 4 to 12 carbonatoms, or a trans-esterification reaction between a terephthalate and aprimary alkyl alcohol containing 4 to 12 carbon atoms. In addition, theepoxy-based alkyl ester compound may be prepared by atrans-esterification reaction between epoxidized oil and a primary alkylalcohol containing 4 or 8 carbon atoms.

As a terephthalate used as a raw material to prepare theterephthalate-based material, an alkyl group of substituted ester groupsat opposite sides of a benzene ring may have 1 to 12 carbon atoms,preferably, 4 to 12 carbon atoms. The C₄-C₁₂ primary alkyl alcohol maybe one or more selected from the group consisting of butyl alcohol,isobutyl alcohol, 2-ethylhexyl alcohol, octyl alcohol, and isononylalcohol.

In addition, the primary alkyl alcohol containing 4 to 8 carbon atomsused as a raw material to prepare the epoxy-based alkyl ester compoundmay be one or more selected from the group consisting of butyl alcohol,isobutyl alcohol, 2-ethylhexyl alcohol, and octyl alcohol. In this case,an alkyl group of the alcohol may correspond to R₂ of Formula 1 in theepoxy-based alkyl ester compound of Formula 1 after the reaction iscompleted.

The epoxidized oil may be, for example, epoxidized soybean oil,epoxidized castor oil, epoxidized linseed oil, epoxidized palm oil,epoxidized stearic acid, epoxidized oleic acid, epoxidized tall oil,epoxidized linoleic acid, or a mixture thereof, and vegetable oil may bea compound into which a certain content of epoxy groups is introducedthrough an epoxidation reaction.

The epoxidized oil may be, for example, represented by Formula 2 below,and may contain three ester groups in a single molecule and include acertain content of epoxy groups.

The epoxidized oil of Formula 2 is provided as one example.

In addition, the epoxidized oil may have an iodine value of less than 4g 12/100 g, and the iodine value is unlikely to vary during atrans-esterification reaction and thus may be almost the same as theiodine value of the epoxy-based alkyl ester compound, which is areaction product. Characteristics of the iodine value are the same asthose of the iodine value of the epoxy-based alkyl ester compound asdescribed above.

When a trans-esterification reaction occurs between the epoxidized oiland the C₄ or C₈ alkyl alcohol, all the three ester groups may beseparated, and, accordingly, three or more epoxy-based ester compoundsin which the alkyl group of the alcohol is newly linked may be formed.

The term “trans-esterification reaction” as used herein refers to areaction in which, as described in Reaction Scheme 1, an alcohol reactswith an ester group and thus R″ of the ester group is interchanged withR′ of the alcohol:

According to an embodiment of the present invention, when thetrans-esterification reaction occurs, three types of ester compositionsmay be produced according to three cases in which an alkoxide of analcohol attacks carbon atoms of two ester groups (RCOOR″) present in anester-based compound; an alkoxide of an alcohol attacks carbon atoms ofan ester group (RCOOR″) present in an ester-based compound; and there isno reaction therebetween.

In addition, the trans-esterification reaction is advantageous in thatwastewater problems are not caused and a reaction rate is high, comparedto an esterification reaction between an acid and an alcohol.

For example, the terephthalate-based material may be prepared byproducing a mixture of di(2-ethylhexyl)terephthalate,butyl(2-ethylhexyl)terephthalate, and dibutyl terephthalate by thetrans-esterification reaction between di(2-ethylhexyl)terephthalate andbutyl alcohol. The three terephthalates may be included in the mixturein amounts of 3.0 wt % to 70 wt %, 0.5 wt % to 50 wt %, and 0.5 wt % to85 wt %, respectively, in particular, 10 wt % to 50 wt %, 0.5 wt % to 50wt %, and 35 wt % to 80 wt %, respectively, based on a total weight ofthe mixture. When the amounts of the three terephthalates are within theabove ranges, a terephthalate-based material (mixture) with highmanufacturing efficiency, high processability and a high absorption ratemay be obtained.

In addition, a composition ratio of the mixture prepared by thetrans-esterification reaction may be controlled according to the amountof an alcohol added.

The amount of the added alcohol may range from 0.1 parts by weight to89.9 parts by weight, in particular, 3 parts by weight to 50 parts byweight, more particularly, 5 parts by weight to 40 parts by weight, withrespect to 100 parts by weight of the terephthalate.

As the amount of the added alcohol increases, a mole fraction of theterephthalate participating in the trans-esterification reactionincreases, and thus the amounts of the two terephthalates, whichreaction products, of the mixture may increase, and the amount ofunreacted terephthalate may decrease in accordance therewith.

According to an embodiment of the present invention, a molar ratio of aterephthalate to an alcohol, which are reactants, may range, forexample, from 1:0.005 to 5.0, from 1:0.05 to 2.5, or from 1:0.1 to 1.0.When the molar ratio thereof is within the above range, a plasticizerwith high manufacturing efficiency and significantly enhancedprocessability may be obtained.

However, the composition ratio of the mixture of threeterephthalate-based materials is not limited to the above-describedranges, and the composition ratio thereof may be varied by furtheradding any one of the three terephthalates, and a detailed descriptionof suitable mixing composition ratios has already been provided above.

According to an embodiment of the present invention, thetrans-esterification reaction may be performed at a reaction temperatureof 120° C. to 190° C., preferably 135° C. to 180° C., more preferably,141° C. to 179° C., for 10 minutes to 10 hours, preferably, 30 minutesto 8 hours, more preferably, for 1 hour to 6 hours. When the reactiontemperature and time are within the above ranges, a mixture ofterephthalate-based materials with a desired composition ratio may beeffectively obtained. At this time, the reaction time may be calculatedfrom the time at which a reaction starts at the reaction temperatureafter heating reactants.

The trans-esterification reaction may be performed in the presence of anacid catalyst or a metal catalyst, and, in this case, the reaction timemay be shortened.

The acid catalyst may be, for example, sulfuric acid, methanesulfonicacid, p-toluenesulfonic acid, or the like, and the metal catalyst maybe, for example, an organic metal catalyst, a metal oxide catalyst, ametal salt catalyst, or a metal.

The metal component may be, for example, any one selected from the groupconsisting of tin, titanium, and zirconium, or a mixture of two or moreof these metals.

In addition, the method may further include, after thetrans-esterification reaction, removing an unreacted alcohol andreaction byproducts, for example, an ester-based compound represented byFormula 3, by distillation.

The distillation process may be, for example, two-stage distillation forseparating the alcohol and the reaction byproducts using a differencebetween boiling points thereof.

As another example, the distillation process may be mixed distillation.In this case, an ester-based plasticizer composition with a desiredcomposition ratio may be relatively stably obtained. The mixeddistillation refers to simultaneous distillation of butanol and reactionbyproducts.

Generally, a trans-esterification reaction used to prepare anepoxy-based alkyl ester compound is also applied in the same manner asin the reaction for preparing a terephthalate-based material, butspecific reaction conditions and the like may differ from each other.For example, there are differences as follows.

The trans-esterification reaction may be performed at a reactiontemperature of 40° C. to 230° C., preferably 50° C. to 200° C., morepreferably, 70° C. to 200° C., for 10 minutes to 10 hours, preferably.30 minutes to 8 hours, more preferably, for 1 hour to 4 hours. When thereaction temperature and time are within the above ranges, a desiredepoxy-based alkyl ester compound may be effectively obtained. At thistime, the reaction time may be calculated from the time at which areaction starts at the reaction temperature after heating reactants.

In addition, the method may further include removing a polyhydricalcohol and reaction byproducts produced after the trans-esterificationreaction and the unreacted alcohol by purification, washing, anddistillation.

The purification process may be performed by, in particular, cooling toand maintaining at a temperature of 80° C. to 100° C. for a certainperiod of time after the trans-esterification reaction. In this case,layer separation occurs wherein an upper layer may include anepoxy-based alkyl ester, and an alcohol, and a lower layer may includeglycerin and other byproducts. Next, to neutralize a catalyst,neutralization and washing may be induced by adding an aqueous solutionfor neutralizing a catalyst.

The neutralization and washing processes may be performed after, first,separating the lower layer mainly including reaction byproducts, and inthe neutralization and washing processes, the byproducts included in thelower layer may be dissolved in water to be discharged, and through asubsequently repeated washing process, the unreacted alcohol and watermay be recovered and removed.

However, it may be necessary to vary the neutralization and washingprocesses according to the number of carbon atoms of an alcohol used inthe t s-esterification reaction.

For example, in a case in which butanol with 4 carbon atoms is used,when the neutralization and washing processes are immediately performed,wastewater generation problems occur, and thus, butanol may bepreviously removed by distillation. However, in this case, catalyticactivity remains, and thus there may be other problems, i.e., occurrenceof an inverse reaction between glycerol as a reaction byproduct and anepoxy-based alkyl ester as a reaction product to produce an epoxidizedoil-like material such as a diglyceride, a triglyceride, or the like,and, accordingly, there is a need to pay attention to the design ofmanufacturing processes.

In addition, as another example, when 2-ethylhexyl alcohol with 8 carbonatoms is used, the 2-ethylhexyl alcohol has low solubility in water, andthus there is no wastewater generation problem and, accordingly, boththe case of removing an alcohol after the neutralization and washingprocesses and the case of performing the neutralization and washingprocesses after removal of the lower layer including reaction byproductsmay be performed without severe problems.

In addition, in the case of preparing the epoxy-based alkyl estercompound, physical properties of the prepared epoxy-based alkyl estercompound may vary according to the type or amount of catalyst used, andphysical properties, yield, or quality of products may vary according toreaction time or the amount of a primary alkyl alcohol reacted withepoxidized oil.

In particular, in the process of preparing an epoxy-based alkyl estercompound, NaOMe may be preferably used as a catalyst, and, when sodiumhydroxide or potassium hydroxide is used as a catalyst, the color of theprepared epoxy-based alkyl ester compound may not meet its standard, andan epoxidation index, the amount of oxirane, and the like of theepoxy-based alkyl ester compound may not have desired values.

In addition, the amount of the catalyst may range from 0.1 wt % to 2.0wt %, preferably, from 0.1 wt % to 1.0 wt %, with respect to a totalweight of the epoxidized oil which is a reaction raw material. When theamount of the catalyst is within the above range, it may be mosteffective in terms of reaction rate, and, when the amount of thecatalyst is outside the above range, an epoxidation index and the likeof the epoxy-based alkyl ester compound may not meet quality standardsdue to a failure in adjusting the amount of the catalyst.

In preparation of the epoxy-based alkyl ester compound, amounts ofepoxidized oil and a primary alkyl alcohol added may be an importantfactor. The primary alkyl alcohol may be added in an amount of 30 partsby weight to 100 parts by weight with respect to the amount of theepoxidized oil. When the amount of the primary alkyl alcohol is lessthan 30 parts by weight, a reaction does not occur efficiently, and thusresidual epoxidized oil or impurities such as a dimerized material ofepoxidized oil, and the like may remain in an excess amount, and, whenthe amount of the primary alkyl alcohol is 100 parts by weight or more,the amount of a residual alcohol to be separated is greater than theamount of a product in the purification process, and thus problems interms of energy and manufacturing efficiency may occur during theprocess.

As described above, after preparing the terephthalate-based material andthe epoxy-based alkyl ester compound, a process of mixing the twocompounds may be performed. A mixing ratio may be appropriately selectedfrom ranges from 99:1 to 1:99, and the two compounds may be mixed in theabove-described mixing weight ratio.

In addition, the plasticizer compound according to the present inventionmay further include epoxidized oil, in addition to theterephthalate-based material and the epoxy-based alkyl ester compound.

In the case of a mixed plasticizer composition of theterephthalate-based material and the epoxy-based alkyl ester compound,thermal resistance from among a variety of physical properties may berelatively poor, and such a thermal resistance property may becompensated for by further adding the epoxidized oil.

The epoxidized oil may be, for example, epoxidized soybean oil,epoxidized castor oil, epoxidized linseed oil, epoxidized palm oil,epoxidized stearic acid, epoxidized oleic acid, epoxidized tall oil,epoxidized linoleic acid, or a mixture thereof. Preferably, theepoxidized oil is epoxidized soybean oil (ESO) or epoxidized linseed oil(ELO), but the present invention is not limited thereto.

In addition, the epoxidized oil may be included in an amount of 1 partby weight to 100 parts by weight, preferably, 10 parts by weight to 100parts by weight, preferably, 20 parts by weight to 100 parts by weight,with respect to 100 parts by weight of the mixture of theterephthalate-based material and the epoxy-based alkyl ester compound.When the amount of the epoxidized oil is within the above ranges, aplasticizer compound with suitably excellent mechanical and physicalproperties and thermal resistance properties may be obtained.

Furthermore, when a terephthalate-based product and epoxidized oil areused in combination, an overall freezing point of the plasticizercomposition may be further reduced, and thus the plasticizer compositionhas a much lower freezing point than that of an epoxy-based plasticizercomposition, and thus a plasticizer composition without limitation onuse even during the winter season may be provided.

Resin Composition

According to an embodiment of the present invention, there is provided aresin composition including: 100 parts by weight of a resin; and 5 partsby weight to 150 parts by weight of the above-described plasticizercomposition.

The resin may be one or more resin selected from ethylene vinyl acetate,polyethylene, polypropylene, polyketone, polyvinyl chloride,polystyrene, polyurethane, and thermoplastic elastomers, and theplasticizer composition may be included in an amount of 5 parts byweight to 150 parts by weight, 40 parts by weight to 100 parts byweight, or 40 parts by weight to 50 parts by weight, with respect to 100parts by weight of the resin, thereby providing a resin compositioneffective in compound formulation, sheet formulation, and plastisolformulation.

Since the resin composition includes the above-described plasticizercompound, the resin composition may be applied to a variety ofapplications, such as flooring materials, wallpaper, interior materialsfor automobiles, sheets, films, hoses, electric wires, and the like, andmay exhibit basic mechanical and physical properties such as tensilestrength, elongation rate, plasticizing efficiency, and volatile lossthat are the same as or superior to those of existing plasticizers.

According to an embodiment of the present invention, the resincomposition may further include a filler.

The amount of the filler may range from 0 parts by weight to 300 partsby weight, preferably, 50 parts by weight to 200 parts by weight, morepreferably, 100 parts by weight to 200 parts by weight, based on 100parts by weight of the resin.

The filler may be any filler known in the art and is not particularlylimited. For example, the filler may be one selected from silica,magnesium carbonate, calcium carbonate, hard charcoal, talc, magnesiumhydroxide, titanium dioxide, magnesium oxide, calcium hydroxide,aluminum hydroxide, aluminum silicate, magnesium silicate, bariumsulfate, and mixtures thereof.

The resin composition may further include other additives such as astabilizer and the like according to need.

The amount of the other additives such as a stabilizer and the like mayrange, for example, from 0 parts by weight to 20 parts by weight,preferably, from 1 part by weight to 15 parts by weight, based on 100parts by weight of the resin.

The stabilizer may be, for example, a calcium-zinc-based (Ca—Zn-based)stabilizer such as a Ca—Zn composite stearate, or the like, but is notparticularly limited thereto.

1. A plasticizer composition comprising: a terephthalate-based material;and an epoxy-based alkyl ester compound represented by Formula 1 belowwherein a weight ratio of the terephthalate-based material to theepoxy-based alkyl ester compound is 90:10 to 50:50, and the epoxy-basedalkyl ester compound is a single compound or a mixture of two or morecompounds, wherein the terephthalate-based material is a compoundselected from the group consisting of di(2-ethylhexyl)terephthalate(DEHTP), diisononyl terephthalate (DINTP), dibutyl terephthalate (DBTP),butyl isononyl terephthalate (BINTP), butyl(2-ethylhexyl)terephthalate(BEHTP), and (2-ethylhexyl)isononyl terephthalate (EHINTP):

wherein, in Formula 1, R1 is a C8-C20 alkyl group or an alkyl groupcontaining one or more epoxy groups, and R2 is a C4 or C8 alkyl group.2.-4. (canceled)
 5. The plasticizer composition of claim 1, wherein theepoxy-based alkyl ester compound has an iodine value of less than 4 gI2/100 g.
 6. The plasticizer composition of claim 1, wherein theepoxy-based alkyl ester compound has an epoxidation index (E.I.) of 1.5or more.
 7. The plasticizer composition of claim 1, further comprisingepoxidized oil.
 8. The plasticizer composition of claim 7, wherein theepoxidized oil may be included in an amount of 1 part by weight to 100parts by weight with respect to a weight of a mixture of theterephthalate-based material and the epoxy-based alkyl ester compound.9. The plasticizer composition of claim 7, wherein the epoxidized oilcomprises one or more selected from the group consisting of epoxidizedsoybean oil, epoxidized castor oil, epoxidized linseed oil, epoxidizedpalm oil, epoxidized stearate, epoxidized oleate, epoxidized tall oil,and epoxidized linoleate. 10.-14. (canceled)
 15. A resin compositioncomprising: 100 parts by weight of a resin; and 5 parts by weight to 150parts by weight of the plasticizer composition of claim
 1. 16. The resincomposition of claim 15, wherein the resin comprises one or moreselected from the group consisting of ethylene vinyl acetate,polyethylene, polypropylene, polyketone, polyvinyl chloride,polystyrene, polyurethane, and thermoplastic elastomers.